FIG. 1 is a planar section showing a motor in accordance with the conventional art, and FIGS. 2 and 3 are views respectively showing a stator and a rotor in accordance with the conventional art. As shown in FIG. 1, the conventional motor comprises a stator 11 that is fixedly installed, and a rotor 21 disposed to be rotatable with respect to the stator 11. The rotor 21 is provided with a pole 22 protruding in a radius direction. The stator 11 is formed by laminating a plurality of steel plates, each steel plate having a plurality of the poles 22 therein. A stator coil 15 for forming a magnetic field is wound on each pole 12 of the stator 11.
When the rotor 21 is rotated as power is applied to the stator coil 15, the pole 12 of the stator 11 and a pole 22 of the rotor 21 come closer to each other. Here, noise occurs by a blade passage frequency (BPF).
Since the rotor 21 is rotated with a high rpm corresponding to 30˜80 thousands, noise may severely occur even by a small factor to generate noise.
In order to solve the problem, as shown in FIG. 2, a space between the poles 12 of the stator 11 was filled by a molding material 17 formed of a synthetic resin member, etc. Also, as shown in FIG. 3, a molding material 27 formed of a synthetic resin member was formed between the poles 22 of the rotor 21 thereby to reduce noise.
However, when the molding materials 17 and 27 are formed in the conventional switched reluctance motor, a passage of air that flows along an axial line of the rotor 21 thus to cool the stator 11 and the rotor 21 is decreased in size or blocked. Accordingly, the temperature of the stator 11 and the rotor 21 is risen, thereby to cause a forcible deterioration of components and a function lowering of the motor.